Problem: $ { \left[\begin{array}{rr}{4} & {1} \\ {-1} & {-1} \\ {4} & {0}\end{array}\right]+\left[\begin{array}{rr}{3} & {2} \\ {4} & {-2} \\ {0} & {-2}\end{array}\right] = {?} } $
To find the sum of two matrices, add the corresponding items between each matrix. ${\left[\begin{array}{rr}{4}+{3} & {1}+{2} \\ {-1}+{4} & {-1}+{-2} \\ {4}+{0} & {0}+{-2}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{7} & {3} \\ {3} & {-3} \\ {4} & {-2}\end{array}\right]}$